Insulating caisson for sealing and insulating storage tank

Abstract

The invention relates to an insulated caisson (7) for a sealed, insulated storage tank intended to contain liquefied gas, said caisson comprising a top plate (21), a bottom plate (22) spaced apart from said top plate (21), and side plates (23, 24). The side panels (23, 24) delimit an interior space (25) of the insulated caisson and comprise longitudinal side panels (23) and transverse side panels (24). A plurality of internal spacers (33, 34) demarcate the internal space (25). The plurality of inner spacers (33, 34) includes transverse inner spacers (34) and longitudinal inner spacers (33). The transverse side panels (24) have mortises (60, 160, 360) extending in a vertical plane and appearing in the interior space (25), each of the mortises (60, 160, 360) receiving one end (36, 336) of one of the longitudinal interior spacers (33), and the ends (36, 336) being secured into the mortises (60, 160, 360) of the transverse side panels (24).

Description

Technical Field

[0001] The present invention relates to the field of sealed thermally insulated film tanks. In particular, the present invention relates to the field of sealed thermally insulated tanks for storing and / or transporting liquefied gases at low temperatures, such as tanks for transporting, for example, liquefied petroleum gas (LPG) at temperatures between -50°C and 0°C or tanks for transporting liquefied natural gas (LNG) at about -162°C at atmospheric pressure. These tanks can be installed on land or on floating structures. In the case of floating structures, the tanks can be intended for transporting liquefied gas or for receiving liquefied gas used as fuel to drive the floating structure. Background Art

[0002] The prior art discloses a sealed insulated tank integrated in a load-bearing structure, the tank comprising a tank wall fixed to the load-bearing wall of the load-bearing structure, the tank wall having an insulating barrier retained on the load-bearing wall and a sealing membrane supported by the insulating barrier in the thickness direction from the outside to the inside of the tank.

[0003] As is known, in such tank walls, the insulating barrier may comprise a plurality of juxtaposed insulating caissons comprising a bottom plate, a top plate, side plates and an internal web defining a space into which the perlite is introduced.

[0004] When in use, the walls of the tank are subject to a variety of loads. In particular, the walls are subject to compressive forces due to the loading of the tank, thermal stresses when cooling the tank, and forces due to the dynamic impact of the fluid contained in the tank. Summary of the invention

[0005] It has been observed that in the aforementioned insulated caissons, the side panels tend to buckle when high compressive forces are applied to the insulated caisson in the thickness direction of the tank wall, especially high compressive forces taking into account the dynamic impact of the fluid on the tank wall.

[0006] The invention is therefore based on the idea of ​​providing an insulated caisson having side panels which are less susceptible to buckling.

[0007] According to one embodiment, the present invention provides an insulated caisson for a sealed insulated storage tank intended to contain liquefied gas, the insulated caisson comprising a top plate, a bottom plate vertically spaced from the top plate, and side plates,

[0008] The side plates extend in a vertical direction and connect the bottom plate and the top plate along the edge of the bottom plate and the edge of the top plate so as to define the inner space of the insulated caisson.

[0009] The side panels include longitudinal side panels and transverse side panels, the longitudinal side panels extend in the longitudinal direction and the transverse side panels extend in the transverse direction, the transverse direction is orthogonal to the longitudinal direction, and the longitudinal direction and the transverse direction are orthogonal to the vertical direction,

[0010] The insulated caisson further comprises a plurality of internal partitions arranged in a vertical plane and dividing the internal space into a plurality of compartments, the compartments being filled with insulating fillers,

[0011] The plurality of internal spacers include transverse internal spacers extending in the transverse direction and spaced apart from each other in the longitudinal direction, and longitudinal internal spacers extending in the longitudinal direction and spaced apart from each other in the transverse direction,

[0012] The transverse side panels have tongue and grooves extending in a vertical plane and appearing in the inner space, each of the tongue and groove receives an end of one of the longitudinal inner spacers, and the end is fixed to the tongue and groove of the transverse side panels.

[0013] Fixing the ends of the longitudinal inner spacers in the tongue and groove improves the resistance of the transverse side panels to buckling. Correspondingly, such fixing keeps the ends of the longitudinal inner spacers in the tongue and groove, and this also improves the resistance of the longitudinal inner spacers to buckling.

[0014] According to some embodiments, such an insulated caisson may have one or more of the following features.

[0015] According to one embodiment, the transverse side panels preferably have a maximum thickness in the longitudinal direction which is strictly greater than the maximum thickness of the longitudinal side panels in the transverse direction. This further increases the resistance of the transverse side panels to buckling.

[0016] The mortise and tenon have various cross-sections. According to one embodiment, the mortise and tenon has a dovetail mortise-shaped cross-section orthogonal to the vertical direction, and the end of the longitudinal internal spacer has a dovetail shaped cross-section orthogonal to the vertical direction. These dovetail cross-sections tend to retain the lateral side panels by preventing them from buckling toward the outside of the insulated caisson (in other words, in a direction away from the interior space of the insulated caisson). This further increases the resistance of the lateral side panels to buckling. According to another embodiment, the mortise and tenon and the end of the longitudinal internal spacer have a rectangular cross-section orthogonal to the vertical direction.

[0017] According to one embodiment, the longitudinal internal spacers each have a series of first slots, and the transverse internal spacers each have a series of second slots, which are complementary to the first slots. This allows the internal spacers to be interlocked and installed in the interior space of the insulated caisson. According to one embodiment, the first slots face the bottom plate and the second slots face the top plate.

[0018] According to one embodiment, the transverse side panels have spacer portions, each of which extends between two adjacent tongue grooves or between a tongue groove and a longitudinal side panel.

[0019] Thus, the spacing portion defines the edge of two adjacent tongues.Thus, the transverse side panel provided with the tongue can be made from a limited number of parts if the spacing portion is the fixed part, or as a single part if the transverse side panel is formed in one piece.

[0020] The spacer portion can be made in various ways.

[0021] According to one embodiment, the lateral side plate comprises an outer plate, and the spacer portion is fixed to the outer plate on the surface of the outer plate facing the inner space of the insulated caisson. For example, the spacer portion is fixed to the outer plate by nails or screws or nails passing through the outer plate, or by adhesive bonding, or by adhesive bonding and nailing.

[0022] Thus, the geometry and / or dimensions of the spacing portions may be easily adapted with a view to making it easier to introduce the insulating filler into the compartments without modifying the outer panels.

[0023] According to one embodiment, the spacing part is an inner plate. According to a particular embodiment, the inner plate contacts the top plate and the bottom plate. This can make it easier to introduce the insulating filler into the compartment, especially if the insulating filler is in the form of glass wool. In particular, the inner plate does not form a shoulder that could hinder the insertion of the glass wool, and the thickness of the inner plate in the longitudinal direction can be adjusted according to the available glass wool elements.

[0024] According to one embodiment, the spacing part is an inner splint. According to a specific embodiment, the inner splint is spaced apart from the bottom plate and the top plate in the vertical direction. Therefore, the inner splint defines the edges of two adjacent tongues and grooves while being spaced apart from the bottom plate and the top plate.

[0025] According to another embodiment, the spacing portion is integral with the transverse side plate, in other words the transverse side plate with the spacing portion is integral and the tongue and groove is formed in the thickness of the transverse side plate in longitudinal direction, for example by machining in the transverse side plate.

[0026] This makes it easier to obtain the desired positions of the tongues and grooves within given dimensional tolerances, since these positions do not depend on the fixing of a plurality of spacer parts.

[0027] According to one embodiment, the ends of the longitudinal inner spacers are fixed to the transverse side panels by means of nails, or screws or nails which pass through the transverse side panels and are fixed in the end faces of the longitudinal inner spacers.

[0028] In this way, it is easy to fix the ends of the longitudinal inner spacers in the tongue and groove.

[0029] The side panels are joined to each other in various ways. According to one embodiment, the longitudinal side panels and the transverse side panels are fixed to each other by means of screws or nails or nails, or by adhesive bonding. According to another embodiment, the longitudinal side panels and the transverse side panels are held to each other by matching shapes.

[0030] According to one embodiment, the longitudinal interior spacers and the transverse interior spacers contact the top plate and the bottom plate.

[0031] This increases the resistance of the insulated caisson to compressive forces in the vertical direction.

[0032] According to one embodiment, each longitudinal internal spacer has a center plate and a protrusion formed at one end of the center plate, each of the protrusions forming the end of the longitudinal internal spacer received in one of the tongues and interacting with an adjacent surface of the tongue, the adjacent surface being contained in a horizontal plane that is orthogonal to the vertical direction and located between the top plate and the bottom plate.

[0033] According to one embodiment, each longitudinal internal spacer has an upper longitudinal strip mounted on the central panel and in contact with the top panel, and a lower longitudinal strip mounted on the central panel and in contact with the bottom panel.

[0034] Thus, the longitudinal inner spacers have an I-beam cross section orthogonal to the vertical direction. This further increases the resistance of the longitudinal inner spacers to buckling.

[0035] According to one embodiment, the longitudinal side panels have additional tongues and tongues extending in a vertical plane and emerging in said inner space, each of said additional tongues and tongues receiving one end of one of said transverse inner spacers and said end being fixed in said additional tongue and tongue of said longitudinal side panels.

[0036] Fixing the ends of the transverse inner spacers in the additional tongue and groove improves the resistance of the longitudinal side panels to buckling. Correspondingly, such fixing keeps the ends of the transverse inner spacers in the tongue and groove, and this also improves the resistance of the transverse inner spacers to buckling.

[0037] According to one embodiment, the additional tongue has a dovetail-shaped cross section orthogonal to the vertical direction, and the end of the transverse internal spacer has a dovetail-shaped cross section orthogonal to the vertical direction. These dovetail-shaped cross sections tend to retain the longitudinal side panels by preventing them from buckling toward the outside of the insulated caisson (in other words, in a direction away from the interior space of the insulated caisson). This further increases the resistance of the transverse side panels to buckling. According to another embodiment, the additional tongue and the end of the transverse internal spacer have a rectangular cross section orthogonal to the vertical direction.

[0038] According to one embodiment, each transverse internal spacer has a center plate and an additional protrusion formed at one end of the center plate, each of the additional protrusions forming the end of the transverse internal spacer received in one of the additional tongues and grooves and interacting with an adjacent surface of the additional tongue and groove, the adjacent surface being contained in a horizontal plane, which is orthogonal to the vertical direction and is located between the top plate and the bottom plate.

[0039] According to one embodiment, each transverse internal spacer has a plurality of upper transverse slats mounted on the center plate and in contact with the top plate, and a plurality of lower transverse slats mounted on the center plate and in contact with the bottom plate, the upper transverse slats extending between two adjacent upper longitudinal slats or between the upper longitudinal slats and the longitudinal side plates, and the lower transverse slats extending between two adjacent lower longitudinal slats or between adjacent lower longitudinal slats and the longitudinal side plates.

[0040] Thus, the transverse inner spacers have an I-beam cross-section orthogonal to the vertical direction. This further increases the resistance of the transverse inner spacers to buckling.

[0041] According to one embodiment, the bottom plate projects beyond said lateral side plates so as to have a lip located outside the inner space of the insulating caisson, and at least one clamping plate is arranged on the lip.

[0042] According to one embodiment, the present invention also provides a sealed insulated storage tank integrated in a load-bearing structure, the tank having a tank wall fixed to the load-bearing wall of the load-bearing structure, in the thickness direction from the outside to the inside of the tank, the tank wall having an insulating barrier maintained on the load-bearing wall and a sealing membrane supported by the insulating barrier, the insulating barrier comprising a plurality of juxtaposed insulating caissons, at least one of the insulating caissons being any one of the aforementioned embodiments, and the vertical direction of the insulating caisson is parallel to the thickness direction.

[0043] Since the transverse side panels and longitudinal internal spacers of the insulated caisson are more resistant to buckling, the tank wall can resist higher compressive forces in the thickness direction. The top plate of the insulated caisson can form a supporting surface for the sealing membrane.

[0044] According to one embodiment, the insulating barrier is held on the load-bearing wall by anchoring members.

[0045] According to the embodiment in which the bottom plate of the insulated caisson has the aforementioned lip and cleats, the anchoring member interacts with the cleats of said insulated caisson.

[0046] In one embodiment, the liquefied gas is LNG, i.e. a mixture with a high methane content stored at a temperature of about -162° C. at atmospheric pressure. Other liquefied gases are also conceivable, in particular ethane, propane, butane or ethylene. The liquefied gas may also be stored under pressure, for example at a relative pressure of between 2 bar and 20 bar, and in particular at a relative pressure of about 2 bar. The tanks may be produced using various technologies, in particular in the form of integrated membrane tanks or self-supporting tanks.

[0047] Such a tank may be part of an onshore storage facility for storing LNG, for example, or may be installed in coastal waters or offshore in a floating structure deepwater structure, in particular an LNG carrier, a floating storage and regasification unit (FSRU), a floating production storage and offloading (FPSO) unit, etc. Such a tank may also be used as a fuel tank on any type of transport vessel.

[0048] According to one embodiment, a transport ship for transporting liquefied gas includes a double hull and the aforementioned storage tanks arranged in the double hull.

[0049] According to one embodiment, the present invention also provides a transportation system for liquefied gas, which system includes: the aforementioned transport ship, an insulating pipeline and a pump; the insulating pipeline is arranged to connect the storage tank installed in the hull of the transport ship to a floating or onshore storage facility; the pump is used to drive the liquefied gas / fluid flow from the floating or onshore storage facility to the storage tank of the transport ship or from the storage tank on the transport ship to the storage facility through the insulating pipeline.

[0050] According to one embodiment, the present invention also provides a method for loading or unloading such a transport vessel, wherein liquefied gas is transferred from a floating or onshore storage facility to a tank of the transport vessel or from the tank to the storage facility via an insulated pipeline. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] The invention will be better understood and other objectives, details, features and advantages of the invention will become more apparent from the following description of a number of particular embodiments of the invention given purely by way of non-limiting illustration with reference to the accompanying drawings.

[0052] Figure 1 It is a schematic cross-sectional view of the tank wall of a sealed insulated storage tank.

[0053] Figure 2 It is a partial exploded and perspective view of the insulated caisson, and the insulating filler is intentionally omitted from the figure.

[0054] Figure 3 is the bottom view from the bearing wall. Figure 1 Schematic diagram of the tank wall, with the view focused on the insulated caisson.

[0055] Figure 4 According to the first embodiment, Figure 2 A perspective view of the lateral side panels of an insulated caisson and a partial view observed from the interior space of the insulated caisson.

[0056] Figure 5 is a partial top view in cross section of an insulated caisson according to a first embodiment.

[0057] Figure 5A Is from Figure 5 Detail of the drawing shows a variation of the first embodiment.

[0058] Figure 6 It is a partial view of a lateral side plate of the insulated caisson according to the second embodiment, viewed from the inner space of the insulated caisson.

[0059] Figure 7 It is based on Figure 6 A partial top view in cross section of an insulated caisson of an embodiment.

[0060] Figure 8 It is a partial view of a cross section of a lateral side plate of the insulated caisson according to the third embodiment and is observed from the inner space of the insulated caisson.

[0061] Fig. 9 It is a partial view of the transverse side panels and the longitudinal side panels of the insulated caisson according to the fourth embodiment, as viewed from the inner space of the insulated caisson.

[0062] Fig.10 It is shown that according to Fig. 9 A view of the various elements of an insulated caisson of an embodiment.

[0063] Fig.11 It is based on Fig. 9 An exploded view of an insulated caisson of an embodiment.

[0064] Fig.12 is a schematic cutaway diagram of a storage tank in a methane carrier and a loading / unloading dock for the tank. DETAILED DESCRIPTION

[0065] The following describes a sealed thermal insulation film storage tank for storing liquefied gas. The storage tank comprises a plurality of storage tank walls 1.

[0066] Figure 1The tank wall 1 is schematically shown in cross section. As shown, the tank wall 1 has a multilayer structure comprising, from the outside to the inside of the tank: a secondary insulation barrier 2 having a secondary insulation element 7 resting on a load-bearing structure 3; a secondary sealing membrane 4 resting on the secondary insulation barrier 2; a primary insulation barrier 5 having a primary insulation element 8 resting on the secondary sealing membrane 4; and a primary sealing membrane 6 intended to be in contact with the liquefied gas contained in the tank. The primary sealing membrane 6 defines an internal space intended to receive the liquefied gas. By way of example, such a membrane tank is particularly described in patent application FR2877638.

[0067] The load-bearing wall 3 is part of a load-bearing structure, such as the double hull of a transport vessel.

[0068] In particular, the liquefied gas intended to be stored in a tank may be liquefied natural gas (LNG), that is, a gas mixture comprising mainly methane and one or more other hydrocarbons. The liquefied gas may also be ethane or liquefied petroleum gas (LPG), that is, a mixture of hydrocarbons obtained from oil refining, which comprises mainly propane and butane.

[0069] The secondary insulation element 7 takes the form of an insulating caisson. Figure 2 An exploded view of such an insulated caisson 7 is shown.

[0070] The insulating caisson 7 is made of, for example, wood or a composite material and has the general shape of a rectangular parallelepiped.

[0071] The heat-insulating caisson 7 has a top plate 21 , a bottom plate 22 , and side plates 23 , 24 .

[0072] The bottom plate 22 is spaced apart from the top plate 21 in the vertical direction of the heat-insulating caisson 7. When the heat-insulating caisson 7 is installed in the tank wall 1, the vertical direction of the heat-insulating caisson 7 is parallel to the thickness direction E of the tank wall 1 (reference Figure 1 ). In the remainder of this description, the vertical direction of the insulated caisson 7 will therefore be indicated as the thickness direction E by convention.

[0073] The side plates 23, 24 extend in the thickness direction E and connect the bottom plate 22 and the top plate 21 along their edges. Thus, the bottom plate 22, the top plate 21 and the side plates 23, 24 together define an inner space 25 of the insulated caisson 7.

[0074] There are four side panels 23, 24: two longitudinal side panels 23 and two transverse side panels 24. The longitudinal side panels 23 are parallel to each other and extend in the longitudinal direction L. The transverse side panels 24 are parallel to each other and extend in the transverse direction T. The transverse direction T is orthogonal to the longitudinal direction L. In addition, the transverse direction T and the longitudinal direction L are each orthogonal to the thickness direction E.

[0075] The insulated caisson 7 further has longitudinal internal spacers 33 and transverse internal spacers 34. The longitudinal internal spacers 33 extend in the longitudinal direction L and are spaced apart from each other in the transverse direction T, for example at regular intervals. The transverse internal spacers 34 extend in the transverse direction T and are spaced apart from each other in the longitudinal direction L.

[0076] The internal spacers 33, 34 extend in a plane parallel to the thickness direction E and divide the internal space 25 of the insulating caisson 7 into a plurality of compartments 26. The compartments 26 receive insulating fillers. Figure 2 The insulating filler is intentionally omitted from the accompanying drawings of FIG. For example, the insulating filler includes glass wool, cellulose wadding, perlite, aerogel, fumed silica, polymer foam, or a combination of these. The insulating filler can completely fill the compartment 26.

[0077] In addition, the inner spacers 33 , 34 contact the bottom plate 22 and the top plate 21 .

[0078] The interaction between the inner spacers 33 , 34 and between the inner spacers 33 , 34 and the side panels 23 , 24 will be explained in detail below.

[0079] Figure 3 is a schematic diagram of a tank wall 1 in a bottom view as seen from the load-bearing wall 3, thus making it possible to observe the secondary insulation barrier 2 and its anchoring to the load-bearing wall 3. A plurality of the above-mentioned insulating caissons 7 are juxtaposed on the load-bearing wall 3. More specifically, the insulating caissons 7 are arranged in the same orientation in the plane of the load-bearing wall 3. In order to simplify the drawings and the following explanation, Figure 3 Only a single insulated caisson 7 is shown in detail in the center of the drawing. Other adjacent insulated caissons 7 are shown with dotted lines.

[0080] The heat-insulating caisson 7 is anchored to the load-bearing wall 3 at its corners by anchor members 9. Figure 2 The bottom plate 22 protrudes beyond each of the two lateral side plates 24 so as to have a lip 22A located outside the internal space 25. A clamping plate 10 is arranged on each of the ends of the lip 22A. Each clamping plate 10 of the insulated caisson 7 interacts with a corresponding anchoring member 9, and the same anchoring member 9 interacts with the clamping plates 10 of multiple insulated caissons 7. A gasket 11 is provided (at Figure 3 ) to support the insulating caisson 7 at the corners of the insulating caisson and to make the insulating caisson level when the insulating caisson 7 is installed on the bearing wall 3.

[0081] Figure 3Schematically shown are glue beads 40, via which the bottom plate 22 of the insulating caisson 7 is abutted against the load-bearing wall 3. The glue beads 40 serve to compensate for the gap between the load-bearing wall 3 and the flat reference surface. Although not shown, a piece of kraft paper can be inserted between the glue beads 40 and the load-bearing wall 3 to prevent the glue beads from sticking to the load-bearing wall 3. In a variant, the aforementioned kraft paper is omitted, and the secondary insulating caisson 7 is at least partially held on the load-bearing wall 3 by the adhesiveness of the glue beads.

[0082] Figure 4 and Figure 5 A first embodiment of a thermally insulated caisson 7 is shown. Figure 4 A perspective view of the transverse side panels 24 and one of the longitudinal internal spacers 33 is shown from the interior space 25 of the insulated caisson 7 . Figure 5 Parts of this transverse side plate 24 and other elements of the insulating caisson 7 are shown in cross section and in top view (that is, from the top plate 21 in the thickness direction E). Figure 2 in Figure 4 and Figure 5 The insulating filler is intentionally omitted from the accompanying drawings.

[0083] As shown in the figures, the side panels 23, 24 and the internal spacers 33, 34 are each composed of a board (eg, a wood board, in particular a plywood board).

[0084] The side panels 23, 24 are secured to one another in a variety of ways, as will be explained in detail below.

[0085] The transverse side panels 24 have a tongue and groove 60 for each of the longitudinal inner spacers 33. It goes without saying that Figure 4 Another lateral side plate 24 not shown in the figure can have the same tongue and groove 60. Therefore, the following description is also applicable to the other lateral side plate 24.

[0086] For example, by machining in the transverse side plate 24 , a tongue groove 60 is formed in the thickness of the transverse side plate 24 along the longitudinal direction L. Therefore, the transverse side plate 24 has a thickened portion 68 formed integrally with the transverse side plate 24 , each thickened portion 68 extending between two adjacent tongue grooves 60 or between a tongue groove 60 and the longitudinal side plate 23 .

[0087] Each of the tongue and grooves 60 extends in a vertical plane (that is, in a plane parallel to the thickness direction E) and emerges in the inner space 25. One end 36 of the longitudinal inner spacer 33 is received in the tongue and groove 60 corresponding to the longitudinal inner spacer 33. The end 36 is fixed to the tongue and groove 60 of the transverse side plate 24. The end 36 is preferably fixed by means of a plurality of nails 69, one of which is located at the inner space 25. Figure 5In this case, it is preferred that the nail 69 passes through the lateral side plate 24 and is fixed to the end surface 36A (reference Figure 5 ). In this way, it is easy to fix the end 36 in the tongue and groove 60. In a variant, the end 36 can be fixed by screws or nails that preferably pass through the lateral side plate 24 and are fixed in the end face 36A.

[0088] return Figure 4 , the longitudinal internal spacers 33 have a series of slots 54 facing the bottom plate 22. Although not shown, the transverse internal spacers 34 each have a series of complementary slots facing the top plate 21 so that the internal spacers 33, 34 are interlockingly mounted in the internal space 25 of the insulated caisson 7. This type of arrangement with slots is described in patent FR2867831B1, especially in Figures 2 to 5 , Figure 8 and Fig.10 Shown in. Figure 5 Reference 32 in the drawing indicates the interlocking cooperation between the slot 54 of the longitudinal inner spacer 33 and the complementary slot of the transverse inner spacer 34 .

[0089] As mentioned above, the insulated caisson 7 is anchored at its corners to the load-bearing wall 3 by anchoring members 9 interacting with the clamping plates 10 arranged on the lip 22A. It has been observed that the transverse side panels 24 are susceptible to buckling when high compressive forces are applied to the insulated caisson 7 in the thickness direction E, in particular high compressive forces taking into account the dynamic impact of the liquefied gas on the tank wall 1. The fixing of the ends 36 of the longitudinal internal spacers 33 in the tongue and groove 60 increases the resistance of the transverse side panels 24 to buckling. Correspondingly, such fixing keeps the ends 36 of the longitudinal internal spacers 33 in the tongue and groove 60 and this also increases the resistance of the longitudinal internal spacers 33 to buckling.

[0090] refer to Figure 5 The transverse side panels 24 preferably have a maximum thickness in the longitudinal direction L. c , which is strictly greater than the maximum thickness of the longitudinal side plate 23 in the transverse direction T d This further increases the resistance of the lateral side panels 24 to buckling. In the example, c =30mm or 24mm or 21mm or 18mm or 15mm, d =21mm or 18mm or 15mm, and m =18mm or 15mm or 12mm, where m ∈ R ≠ 0.05, which indicates the thickness of the longitudinal inner spacer 33 in the transverse direction T.

[0091] exist Figure 4 and Figure 5In the example shown, the transverse side plate 24 has recesses 24A at both ends thereof. Each recess 24A receives an end 23A of the longitudinal side plate 23. Thus, the longitudinal side plate 23 can be fixed to the transverse side plate 24 by means of its end 23A by means of nails 49 passing through the transverse side plate 24 at the recesses 24A, wherein only one nail is in the transverse side plate 24. Figure 5 . Therefore, regardless of the thickness of the lateral side plate 24, it is easy to fix the longitudinal side plate 23 to the lateral side plate 24. For example, the recess 24A extends through half of the thickness of the lateral side plate 24. In a variation, the longitudinal side plate 23 can be fixed by screws or nails passing through the recess 24A.

[0092] exist Figure 5A In another variant shown, the transverse side panels 24 have no recesses 24A, and the longitudinal side panels 23 are fixed to the transverse side panels 24 by means of their ends 23A by means of nails 491 passing through the ends 23A, wherein only one nail is in Figure 5A Thus, the nail 491 passes through the thinner longitudinal side plate 23. In a variant, the longitudinal side plate 23 can be fixed by screws or nails passing through the end 23A.

[0093] According to another variant, the longitudinal side panels 23 are fixed to the transverse side panels 24 by adhesive bonding.

[0094] The transverse inner spacers 34 are fixed to the longitudinal side panels 23. This fixing can be done in various ways, for example by means of screws or nails or nails.

[0095] refer to Figure 2 , the insulating caisson 7 can additionally have a through hole 27 connected to the inner space 25. The through hole 27 allows an inert gas (for example, nitrogen) to circulate in the inner space 25, the inert gas being used to place the insulating barrier 2 under an inert atmosphere. In this case, the above-mentioned insulating filler is permeable to the gas. In the example shown, the through hole 27 is made in the transverse side plate 24. In a variant, the through hole 27 can also be provided in the longitudinal side plate 23 and / or the bottom plate 22.

[0096] Figure 6 and Figure 7 A second embodiment of the heat-insulating caisson 7 is shown. Figures 1 to 5 Those elements in which the elements are similar or identical have the same reference numerals. It should be specified that Figure 7 Not drawn to scale, the size of some elements have been exaggerated to ensure drawing readability.

[0097] In this embodiment, the lateral side plate 24 has an outer plate 124 and an inner plate 128. The inner plate 128 is fixed to the outer plate 124, more specifically to the surface of the outer plate 124 facing the inner space 25 of the insulated caisson 7. The inner plate 128 is preferably fixed by means of nails 129 passing through the outer plate 124, such as Figure 7 As shown. Such fixing is easy to implement, similar to fixing the end 36 in the tongue and groove 160. In a variant, the inner panel 128 can be fixed to the outer panel 124 in other ways, in particular by means of screws or nails passing through the outer panel 124, or by adhesive bonding, or by adhesive bonding and by nailing. The inner panel 128 and the outer panel 124 are, for example, wooden boards, in particular plywood.

[0098] The inner plate 128 is fixed to the outer plate 124 so that the facing end surfaces of two adjacent plates 128 are spaced apart in the transverse direction T by a distance s (refer to Figure 7 ). Within manufacturing tolerances, the distance s Equal to the thickness of the longitudinal inner spacer 33 in the transverse direction T m The facing end faces and the face of the outer plate 124 facing the interior space 25 thus together form a tongue and groove 160 similar to the tongue and groove 60 described above. Each of the inner plates 128 extends between two adjacent tongue and groove 160 or between a tongue and groove 160 and a longitudinal side plate 23 .

[0099] In this embodiment, it may also be the case that the ends 36 of the longitudinal spacers 33 are preferably fixed in the tongue 160 by means of nails 69 preferably passing through the outer plate 124. In a variant, the ends 36 may be fixed by screws or nails preferably passing through the transverse side plates 24.

[0100] In this embodiment, it may also be the case that the transverse side panels 24 preferably have a maximum thickness in the longitudinal direction L. C , which is strictly greater than the maximum thickness of the longitudinal side plate 23 in the transverse direction T d In the example, C =30mm or 24mm or 21mm or 18mm or 15mm, d =21mm or 18mm or 15mm, and m =18mm or 15mm or 12mm. In a specific embodiment, the inner plate 128 and the outer plate 124 have the same thickness in the longitudinal direction L, for example, equal to 12mm, and this tends to simplify the manufacture of the lateral side plate 24. In another specific embodiment, the inner plate 128 and the outer plate 124 have different thicknesses in the longitudinal direction L, for example, equal to 9mm and 12mm respectively.

[0101] Figure 7It is also shown that the longitudinal side panels 23 can be fixed to the transverse side panels 24, more specifically to the outer panels 124 of the transverse side panels, by means of nails 149 passing through the outer panels 124, wherein only one nail is in Figure 7 . Such fixing is easy to perform due to the moderate thickness of the outer plate 124. In a variant, the longitudinal side plates 23 can be fixed by screws or nails passing through the outer plate 124, or bonded to the outer plate 124 in an adhesive manner.

[0102] The dimension of the inner plate 128 in the thickness direction E is substantially equal to the distance between the bottom plate 22 and the top plate 21 in the thickness direction E, and thus substantially equal to the dimension of the longitudinal internal spacer 33, so as to contact the top plate 21 and the bottom plate 22 when assembling the insulated caisson 7. This can make it easier to introduce the insulating filler into the compartment 26, especially when the insulating filler is in the form of glass wool. Specifically, the inner plate 128 does not form a shoulder that may hinder the insertion of the glass wool, and the thickness of the inner plate 128 in the longitudinal direction L can be adjusted according to the available glass wool elements.

[0103] Figure 8 A third embodiment of the heat-insulating caisson 7 is shown. Figures 1 to 5 Those elements in which the elements are similar or identical have the same reference numerals. It should be specified that Figure 8 Not drawn to scale, the size of some elements have been exaggerated to ensure drawing readability.

[0104] The third embodiment differs from the second embodiment in that the inner plate 128 is replaced by a clamping plate 228. The dimension of the clamping plate 228 in the thickness direction E is strictly smaller than the distance between the bottom plate 22 and the top plate 21 in the thickness direction E. Therefore, the clamping plate 228 is spaced apart from the bottom plate 22 and the top plate 21. The facing end surfaces of the two clamping plates 228 are spaced apart in the transverse direction T by a distance s , thus forming the tongue and groove 160 in a manner similar to the second embodiment. Figure 8 As shown, the clamping plate 228 is placed in the middle in the thickness direction E. Figure 8 The orifice 27 is intentionally omitted from the drawings and may be placed above or below the clamping plate 228 in the thickness direction E.

[0105] The secondary sealing membrane 4 can be made in various ways. According to one embodiment, the secondary sealing membrane 4 comprises a continuous metal strake layer with raised edges. The metal strakes are welded by their raised edges to parallel welding supports fixed to parallel grooves 21R made in the top plate 21 of the thermal insulation caisson 7 (refer to Figure 2 ). The metal strakes are, for example, (i.e., an alloy of iron and nickel) and its coefficient of expansion is usually between 1.2.10 -6 With 2.10-6 K -1 between.

[0106] The primary insulating barrier 5 can be made in various ways. According to one embodiment, the insulating barrier 5 has a plurality of insulating caissons similar to the insulating caissons 7 juxtaposed to one another and resting on the secondary sealing membrane 4 .

[0107] The primary sealing film 6 may be made in various ways. According to one embodiment, the primary sealing film 6 may comprise a continuous metal strake layer with raised edges, similar to the secondary sealing film 4 .

[0108] In a variant, the tank wall 1 may have a single membrane, that is to say, the tank wall 1 may only comprise the insulating barrier 2 and the sealing membrane 4, the sealing membrane 4 being in contact with the liquefied gas.

[0109] Fig. 9 , Fig.10 and Fig.11 A fourth embodiment of the heat-insulating caisson 7 is shown. Figures 1 to 5 Those elements in the drawings that are similar or identical have the same reference numerals.

[0110] Fig. 9 The transverse side panels 24 and the longitudinal side panels 23 of the insulated caisson 7 are partially shown in a perspective view observed from the interior space 25. The transverse side panels 24 have a tongue 360 ​​similar to the tongue 60. In addition, the longitudinal side panels 23 have tongues 369 similar to the tongue 360, each tongue 369 receiving an end of a transverse internal spacer 34, as will be described below. Similar to the first embodiment, the side panels 23, 24 are each composed of a board, such as a wood panel, in particular a plywood panel, and the tongues 360, 369 are formed in the thickness of the side panels 24, 23.

[0111] like Fig. 9 As shown, the tongue and groove 360, 369 extends only over a partial height of the side panels 24, 23 in the thickness direction E. Therefore, the tongue and groove 360, 369 includes an abutment surface 360A, 369A located between the top panel 21 and the bottom panel 22. The abutment surfaces 360A, 369A are horizontal, that is, included in a horizontal plane orthogonal to the thickness direction E. In the example shown, all abutment surfaces 360A, 369A are included in the same horizontal plane. In a variation, the abutment surface 360A can be included in a first horizontal plane, and the abutment surface 369A can be included in a second horizontal plane spaced apart from the first horizontal plane. In a variation, the abutment surfaces 360A, 369A of a given side panel 24, 23 can be included in different horizontal planes.

[0112] Fig. 9It is also shown that the transverse side panels 24 and the longitudinal side panels 23 have end portions 24F, 23F of complementary shape, so that the transverse side panels 24 and the longitudinal side panels 23 are held to each other by matching shapes.

[0113] Similar to the above-described embodiments, in this fourth embodiment, the lateral side panels 24 preferably have a maximum thickness in the longitudinal direction L that is strictly greater than the maximum thickness of the longitudinal side panels 23 in the lateral direction.

[0114] refer to Fig.10 , the transverse internal spacer 33 comprises a central plate 333 having, at each of its two ends, a protrusion 336 intended to be housed in the tongue 360. Similarly, the longitudinal transverse internal spacer 34 comprises a central plate 334 having, at each of its two ends, a protrusion 339 intended to be housed in the tongue 369. The protrusions 336, 339 extend in the thickness direction E only over a partial height of the longitudinal internal spacers 33, 34.

[0115] Fig.10 Also shown is the slot 54 of the longitudinal internal spacer 33. The slot 54 is formed in the center plate 333. As mentioned above, the transverse internal spacer 34 has a slot 53 complementary to the slot 54 so that the internal spacers 33, 34 are interlockingly mounted in the internal space 25 of the insulated caisson 7. The transverse internal spacer 34 further has a shoulder 353, a slot 53 appearing in the shoulder 353, and a shoulder 359 opposite to the shoulder 353 in the thickness direction E. The slots 53, 59 and the shoulders 353, 359 are formed in the center plate 334.

[0116] Fig.11 The inner spacers 33, 34 are shown assembled in an interlocking manner by means of the slots 53, 54 described above.

[0117] For each longitudinal inner spacer 33, a longitudinal strip 363 is fitted on each of the two ends of the center plate 333 in the thickness direction E by means of the groove of the longitudinal strip 363. The longitudinal strip 363 fitted on the protrusion 336 is prevented from translational movement in the longitudinal direction L by the stopper 336T of the protrusion 336. The longitudinal strip 363 is received in the shoulders 353, 359 of the transverse inner spacer 34.

[0118] Similarly, for each transverse inner spacer 34, a transverse slat 364 is mounted on each of the two ends of the central plate 334 in the thickness direction E by means of the grooves of the transverse slat 364. Each transverse slat 364 adjoins one or two longitudinal slats 363. The transverse slat 364 mounted on the protrusion 339 is prevented from translational movement in the transverse direction T by the stopper 339T of the protrusion 339.

[0119] When the insulated caisson 7 is assembled, the protrusion 336 is received in the tongue 360 ​​and rests on the horizontal abutment surface 360A, and the protrusion 339 is received in the tongue 369 and rests on the horizontal abutment surface 369A. The protrusions 336, 339 are preferably fixed to the tongue 360, 369 of the side panels 24, 23 by means of nails, which preferably pass through the side panels 24, 23. In a variant, the protrusions 336, 339 can be fixed in other ways, in particular by nails, by screws, by adhesive bonding, etc.

[0120] Fixing the protrusions 336, 339 in the tongue and groove 360, 369 improves the resistance of the side panels 24, 23 to buckling. Correspondingly, such fixing holds the protrusions 336, 339 in the tongue and groove 360, 369, and this also improves the resistance of the internal spacers 33, 34 to buckling.

[0121] like Fig. 9 As shown, the tongue grooves 360, 369 have a dovetail tongue groove-shaped cross section orthogonal to the thickness direction E. Therefore, the tongue grooves 336, 369 have a dovetail tongue groove-shaped cross section orthogonal to the thickness direction E. These dovetail-shaped cross sections tend to retain the side panels 24, 23 by preventing them from buckling toward the outside of the insulated caisson 7 (in other words, in a direction away from the interior space 25 of the insulated caisson 7). This further improves the resistance of the side panels 24, 23 to buckling.

[0122] In a variant, the tongues and grooves 360 , 369 and the protrusions 336 , 339 may have a rectangular cross section orthogonal to the thickness direction E.

[0123] In particular Fig.11 As shown, the internal spacers 33, 34 provided with the slats 363, 364 have an I-beam cross section orthogonal to the thickness direction E, and when the insulated caisson 7 is assembled, the slats 363, 364 contact the bottom plate 22 and the top plate 21. The internal spacers 33, 34 provided with the slats 363, 364 can therefore better resist buckling.

[0124] refer to Fig.12 , a cross-sectional view of a methane carrier 70 shows a sealed, insulated storage tank 71 of a prismatic general shape installed in a double hull 72 of the carrier. The wall of the storage tank 71 includes a primary sealing membrane intended to be in contact with the LNG contained in the storage tank, a secondary sealing membrane arranged between the primary sealing membrane and the double hull 72 of the carrier, and two insulating barriers arranged between the primary sealing membrane and the secondary sealing membrane and between the secondary sealing membrane and the double hull 72, respectively.

[0125] As known per se, the loading / unloading pipeline 73 arranged on the upper deck of the transport vessel can be connected to a maritime or port terminal by means of appropriate connectors in order to transport the LNG cargo from or to the storage tanks 71 .

[0126] Fig.12 An example of a marine terminal is shown, which has a loading and unloading station 75, an underwater pipeline 76 and an onshore facility 77. The loading and unloading station 75 is a fixed offshore facility with a movable arm 74 and a tower 78 supporting the movable arm 74. The movable arm 74 carries a bundle of flexible insulating hoses 79 that can be connected to the loading / unloading pipeline 73. The orientable movable arm 74 can be suitable for transport ships of all sizes. The connecting pipeline, not shown, extends inside the tower 78. The loading and unloading station 75 makes it possible to load from the onshore facility 77 to the methane transport ship 70 or unload from the methane transport ship to the onshore facility. The onshore facility has a liquefied gas storage tank 80 and a connecting pipeline 81, which is connected to the loading or unloading station 75 via an underwater pipeline 76. The underwater pipeline 76 makes it possible to transport liquefied gas between the loading or unloading station 75 and the onshore facility 77 over long distances (eg 5 km), allowing the methane tanker 70 to remain at a long distance from the shore during loading and unloading operations.

[0127] In order to generate the pressure required for transporting the liquefied gas, a pump carried on board the transport vessel 70 and / or a pump equipped at the shore facility 77 and / or a pump equipped at the loading and unloading station 75 is used.

[0128] Although the invention has been described in connection with a few specific embodiments, it is obvious that the invention is by no means limited thereto and that the invention comprises all technical equivalents of the described means as well as combinations thereof, if the described means fall within the scope of the invention.

[0129] Use of the verb "comprise" or "include" or "have" (including their inflections) does not exclude the presence of other elements or steps than those stated in a claim.

[0130] In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim.

Claims

1. An insulated caisson (7) for a sealed, insulated storage tank intended to contain liquefied gas, the insulated caisson comprising a top plate (21), a bottom plate (22) spaced apart from the top plate (21) in a vertical direction (E), and side plates (23, 24), The side panels (23, 24) extend in the vertical direction (E) and connect the bottom panel (22) and the top panel (21) along the edge of the bottom panel (22) and the edge of the top panel (21) to define an inner space (25) of the thermal insulation caisson. The side panels (23, 24) include longitudinal side panels (23) and transverse side panels (24), the longitudinal side panels (23) extending in a longitudinal direction (L) and the transverse side panels (24) extending in a transverse direction (T), the transverse direction (T) being orthogonal to the longitudinal direction (L), and the longitudinal direction (L) and the transverse direction (T) being orthogonal to the vertical direction, The insulated caisson (7) further comprises a plurality of internal partitions (33, 34) arranged in a vertical plane and dividing the internal space (25) into a plurality of compartments (26), the compartments (26) being filled with insulating fillers, The plurality of internal spacers (33, 34) include transverse internal spacers (34) extending in the transverse direction (T) and spaced apart from each other in the longitudinal direction (L), and longitudinal internal spacers (33) extending in the longitudinal direction (L) and spaced apart from each other in the transverse direction (T), The transverse side panel (24) has a tongue and groove (60, 160, 360) extending in a vertical plane and appearing in the internal space (25), each of the tongue and groove (60, 160, 360) receiving an end (36, 336) of one of the longitudinal internal spacers (33), and the end (36, 336) is fixed to the tongue and groove (60, 160, 360) of the transverse side panel (24).

2. An insulated caisson (7) according to claim 1, wherein the lateral side panels (24) have spacer portions (68, 128, 228), each of which extends between two adjacent tongues and grooves (60, 160, 360) or between the tongue and groove (60, 160, 360) and the longitudinal side panels (23).

3. An insulated caisson (7) according to claim 2, wherein the lateral side panel (24) includes an outer panel (124), and the spacer portion (128, 228) is fixed to the outer panel (124) on the surface of the outer panel (124) facing the internal space (25) of the insulated caisson (7).

4. The insulated caisson (7) according to claim 3, wherein the spacer portion is an inner plate (128) or an inner plywood (228).

5. The insulated caisson (7) according to claim 2, wherein the spacer portion (68) is formed integrally with the lateral side plate (24).

6. An insulated caisson (7) according to any one of claims 1 to 5, wherein the end portions (36, 336) of the longitudinal internal spacers (33) are fixed to the transverse side panels (24) by means of nails (69), or screws or nails, which pass through the transverse side panels (24) and are fixed in the end faces of the longitudinal internal spacers (33).

7. The insulated caisson (7) according to any one of claims 1 to 6, wherein the longitudinal internal spacers (33) and the transverse internal spacers (34) contact the top plate (21) and the bottom plate (22).

8. An insulated caisson (7) according to claim 7, wherein each longitudinal internal spacer (33) has a center plate (333) and a protrusion (336) formed at one end of the center plate (333), each of the protrusions (336) forming the end of the longitudinal internal spacer (33) received in one of the tongues and grooves (360) and interacting with an adjacent surface (360A) of the tongue and groove (360), the adjacent surface (360A) being contained in a horizontal plane, the horizontal plane being orthogonal to the vertical direction (E) and being located between the top plate (21) and the bottom plate (22).

9. An insulated caisson (7) according to claim 8, wherein each longitudinal internal spacer (33) has an upper longitudinal strip (363) mounted on the center plate (333) and in contact with the top plate (21), and a lower longitudinal strip (363) mounted on the center plate (333) and in contact with the bottom plate (22).

10. An insulated caisson (7) according to any one of claims 1 to 9, wherein the longitudinal side panels (23) have additional tongues and grooves (369) extending in a vertical plane and appearing in the internal space (25), each of the additional tongues and grooves (369) receiving an end of one of the transverse internal spacers (34), and the end is fixed to the additional tongue and groove (369) of the longitudinal side panels (23).

11. An insulated caisson (7) according to claim 10, wherein each transverse internal spacer (34) has a center plate (336) and an additional protrusion (339) formed at one end of the center plate (336), each of the additional protrusions (339) forming the end of the transverse internal spacer (34) received in one of the additional tongues and grooves (369) and interacting with an adjacent surface (369A) of the additional tongue and groove (369), the adjacent surface (369A) being contained in a horizontal plane, the horizontal plane being orthogonal to the vertical direction (E) and being located between the top plate (21) and the bottom plate (22).

12. An insulated caisson (7) according to claim 11 in combination with claim 9, wherein each transverse internal spacer (34) has a plurality of upper transverse slats (364) mounted on the center plate (334) and in contact with the top plate (21), and a plurality of lower transverse slats (364) mounted on the center plate (334) and in contact with the bottom plate (22), the upper transverse slats (364) extending between two adjacent upper longitudinal slats (363) or between the upper longitudinal slats (363) and the longitudinal side plate (23), and the lower transverse slats (364) extending between two adjacent lower longitudinal slats (363) or between the lower longitudinal slats (363) and the longitudinal side plate (23).

13. An insulated caisson according to any one of claims 1 to 12, wherein the bottom plate (22) protrudes beyond the lateral side plate (24) to have a lip (22A) located outside the internal space (25) of the insulated caisson (7), and wherein at least one clamping plate (10) is arranged on the lip (22A).

14. A sealed insulated storage tank integrated in a load-bearing structure, the tank having a tank wall (1) fixed to a load-bearing wall (3) of the load-bearing structure, in a thickness direction (E) from the outside to the inside of the tank, the tank wall having an insulating barrier (2) retained on the load-bearing wall (3) and a sealing membrane (4) supported by the insulating barrier (2), the insulating barrier comprising a plurality of juxtaposed insulating caissons, at least one of the insulating caissons (7) being an insulating caisson according to any one of claims 1 to 12, and the vertical direction of the insulating caisson (7) being parallel to the thickness direction (E).

15. A sealed insulated storage tank according to claim 14, wherein the insulating barrier (2) is held on the load-bearing wall (3) by an anchoring member (9), the insulating caisson (7) is an insulating caisson according to claim 13, and the anchoring member (9) interacts with the clamping plate (10) of the insulating caisson (7).

16. A transport ship (70) for transporting liquefied gas, the transport ship having a double hull (72) and a storage tank (71) according to any one of claims 14 to 15, the storage tank being arranged in the double hull.

17. A system for transporting liquefied gas, the system comprising: The transport vessel (70) according to claim 16, the insulating pipeline (73, 79, 76, 81) and the pump; The insulated pipeline is arranged to connect the storage tank (71) installed in the hull of the transport vessel to a floating or onshore storage facility (77); the pump is used to drive the liquefied gas / fluid flow from the floating or onshore storage facility to the storage tank on the transport vessel or from the storage tank on the transport vessel to the floating or onshore storage facility through the insulated pipeline.

18. A method for loading or unloading a transport vessel (70) according to claim 16, wherein liquefied gas is transported from a floating or onshore storage facility (77) to the storage tank (71) on the transport vessel (70) or from the storage tank on the transport vessel to the floating or onshore storage facility via the insulated pipeline (73, 79, 76, 81).

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